The present invention generally relates to improvements in call transfer circuits and more particularly pertains to a line transfer circuit wherein a first subscriber line from a central office is switched to a second subscriber set after a predetermined time delay during ringing of the first subscriber set.
In the field of telephone call transferring circuits, it has been the practice to forward ringing current to another subscriber set after a predetermined time delay or immediately upon assignment. Although such devices work satisfactorily in transferring the ringing current to a second or designated subscriber set, generally, a complex and expensive system is required to carry out such a function and common loop circuits for the transferring and receiving subscriber sets are used. This arrangement does not provide for call transferring between two independent lines and allows the transferring subscriber set to listen in on a conversation that has been directed to a receiving subscriber set.